点击某个元素的时候会出现蓝色

css:
    body {
        -moz-user-select: none; /*火狐*/
        -webkit-user-select: none; /*webkit浏览器*/
        -ms-user-select: none; /*IE10*/
        -khtml-user-select: none; /*早期浏览器*/
        user-select: none;
    }
js:
    document.ondragstart = document.onselectstart = function(){return false;};